Allow Beacon Node to Connect to Bootstrap Node for Peer Discovery (#740)

* start sequence for node to connect to bootstrap nodes

* lint

* maybe warning is more appropiate?

* fix gazelle

* preston's feedback

* add go-ipfs-addr to workspace

* move flag to shared

* removed routed host

WORKSPACE

@@ -760,3 +760,9 @@ go_repository(
     commit = "20f1fb78b0740ba8c3cb143a61e86ba5c8669768",
     importpath = "github.com/hashicorp/golang-lru",
 )
+
+go_repository(
+    name = "com_github_ipfs_go_ipfs_addr",
+    commit = "489e2d62e87b8986d703b3b28d62a7fcc3978222",
+    importpath = "github.com/ipfs/go-ipfs-addr",
+)

beacon-chain/main.go

@@ -70,6 +70,7 @@ VERSION:
 		utils.KeyFlag,
 		utils.GenesisJSON,
 		utils.EnablePOWChain,
+		cmd.BootstrapNode,
 		cmd.DataDirFlag,
 		cmd.VerbosityFlag,
 		cmd.EnableTracingFlag,

beacon-chain/node/p2p_config.go

@@ -23,7 +23,7 @@ var topicMappings = map[pb.Topic]proto.Message{
 }
 
 func configureP2P(ctx *cli.Context) (*p2p.Server, error) {
-	s, err := p2p.NewServer()
+	s, err := p2p.NewServer(ctx.GlobalString(cmd.BootstrapNode.Name))
 	if err != nil {
 		return nil, err
 	}

shared/cmd/flags.go

@@ -71,4 +71,9 @@ var (
 		Name:  "keystore-password",
 		Usage: "Keystore password is used to unlock the keystore so that the users decrypted keys can be used.",
 	}
+	// BootstrapNode tells the beacon node which bootstrap node to connect to
+	BootstrapNode = cli.StringFlag{
+		Name:  "bootstrap-node",
+		Usage: "The address of bootstrap node. Beacon node will connect for peer discovery via DHT",
+	}
 )

shared/p2p/BUILD.bazel

@@ -19,6 +19,7 @@ go_library(
         "@com_github_golang_protobuf//proto:go_default_library",
         "@com_github_ipfs_go_datastore//:go_default_library",
         "@com_github_ipfs_go_datastore//sync:go_default_library",
+        "@com_github_ipfs_go_ipfs_addr//:go_default_library",
         "@com_github_libp2p_go_libp2p//:go_default_library",
         "@com_github_libp2p_go_libp2p//p2p/discovery:go_default_library",
         "@com_github_libp2p_go_libp2p//p2p/host/routed:go_default_library",

shared/p2p/discovery.go

@@ -4,7 +4,8 @@ import (
 	"context"
 	"time"
 
-	host "github.com/libp2p/go-libp2p-host"
+	iaddr "github.com/ipfs/go-ipfs-addr"
+	"github.com/libp2p/go-libp2p-host"
 	ps "github.com/libp2p/go-libp2p-peerstore"
 	mdns "github.com/libp2p/go-libp2p/p2p/discovery"
 	"github.com/sirupsen/logrus"
@@ -18,11 +19,9 @@ var discoveryInterval = 1 * time.Minute
 // mDNSTag is the name of the mDNS service.
 var mDNSTag = mdns.ServiceTag
 
-// startDiscovery protocols. Currently, this supports discovery via multicast
-// DNS peer discovery.
-//
 // TODO(287): add other discovery protocols such as DHT, etc.
-func startDiscovery(ctx context.Context, host host.Host) error {
+// startmDNSDiscovery supports discovery via multicast DNS peer discovery.
+func startmDNSDiscovery(ctx context.Context, host host.Host) error {
 	mdnsService, err := mdns.NewMdnsService(ctx, host, discoveryInterval, mDNSTag)
 	if err != nil {
 		return err
@@ -32,6 +31,21 @@ func startDiscovery(ctx context.Context, host host.Host) error {
 	return nil
 }
 
+// startDHTDiscovery supports discovery via DHT.
+func startDHTDiscovery(ctx context.Context, host host.Host, bootstrapAddr string) error {
+	addr, err := iaddr.ParseString(bootstrapAddr)
+	if err != nil {
+		return err
+	}
+	peerinfo, err := ps.InfoFromP2pAddr(addr.Multiaddr())
+	if err != nil {
+		return err
+	}
+
+	err = host.Connect(ctx, *peerinfo)
+	return err
+}
+
 // Discovery implements mDNS notifee interface.
 type discovery struct {
 	ctx  context.Context

shared/p2p/discovery_norace_test.go

@@ -31,13 +31,13 @@ func TestStartDiscovery_HandlePeerFound(t *testing.T) {
 	defer cancel()
 
 	a := bhost.New(swarmt.GenSwarm(t, ctx))
-	err := startDiscovery(ctx, a)
+	err := startmDNSDiscovery(ctx, a)
 	if err != nil {
 		t.Errorf("Error when starting discovery: %v", err)
 	}
 
 	b := bhost.New(swarmt.GenSwarm(t, ctx))
-	err = startDiscovery(ctx, b)
+	err = startmDNSDiscovery(ctx, b)
 	if err != nil {
 		t.Errorf("Error when starting discovery: %v", err)
 	}

shared/p2p/feed_example_test.go

@@ -8,7 +8,7 @@ import (
 
 // Feeds can be use to subscribe to any type of message.
 func ExampleServer_Feed() {
-	s, err := NewServer()
+	s, err := NewServer("")
 	if err != nil {
 		panic(err)
 	}

shared/p2p/feed_test.go

@@ -23,7 +23,7 @@ func TestFeed_ReturnsSameFeed(t *testing.T) {
 		{a: &testpb.Puzzle{}, b: &testpb.TestMessage{}, want: false},
 	}
 
-	s, _ := NewServer()
+	s, _ := NewServer("")
 
 	for _, tt := range tests {
 		feed1 := s.Feed(tt.a)

shared/p2p/register_topic_example_test.go

@@ -31,7 +31,7 @@ func adapterWithParams(i int) p2p.Adapter {
 func ExampleServer_RegisterTopic() {
 	adapters := []p2p.Adapter{reqLogger, adapterWithParams(5)}
 
-	s, _ := p2p.NewServer()
+	s, _ := p2p.NewServer("")
 
 	var topic string
 	var message proto.Message

shared/p2p/service.go

@@ -26,17 +26,18 @@ type Sender interface {
 
 // Server is a placeholder for a p2p service. To be designed.
 type Server struct {
-	ctx          context.Context
-	cancel       context.CancelFunc
-	mutex        *sync.Mutex
-	feeds        map[reflect.Type]Feed
-	host         host.Host
-	gsub         *pubsub.PubSub
-	topicMapping map[reflect.Type]string
+	ctx           context.Context
+	cancel        context.CancelFunc
+	mutex         *sync.Mutex
+	feeds         map[reflect.Type]Feed
+	host          host.Host
+	gsub          *pubsub.PubSub
+	topicMapping  map[reflect.Type]string
+	bootstrapNode string
 }
 
 // NewServer creates a new p2p server instance.
-func NewServer() (*Server, error) {
+func NewServer(bootstrapNode string) (*Server, error) {
 	ctx, cancel := context.WithCancel(context.Background())
 	opts := buildOptions()
 	h, err := libp2p.New(ctx, opts...)
@@ -57,21 +58,29 @@ func NewServer() (*Server, error) {
 	}
 
 	return &Server{
-		ctx:          ctx,
-		cancel:       cancel,
-		feeds:        make(map[reflect.Type]Feed),
-		host:         h,
-		gsub:         gsub,
-		mutex:        &sync.Mutex{},
-		topicMapping: make(map[reflect.Type]string),
+		ctx:           ctx,
+		cancel:        cancel,
+		feeds:         make(map[reflect.Type]Feed),
+		host:          h,
+		gsub:          gsub,
+		mutex:         &sync.Mutex{},
+		topicMapping:  make(map[reflect.Type]string),
+		bootstrapNode: bootstrapNode,
 	}, nil
 }
 
 // Start the main routine for an p2p server.
 func (s *Server) Start() {
 	log.Info("Starting service")
-	if err := startDiscovery(s.ctx, s.host); err != nil {
-		log.Errorf("Could not start p2p discovery! %v", err)
+
+	if s.bootstrapNode != "" {
+		if err := startDHTDiscovery(s.ctx, s.host, s.bootstrapNode); err != nil {
+			log.Errorf("Could not start peer discovery via DHT: %v", err)
+		}
+	}
+
+	if err := startmDNSDiscovery(s.ctx, s.host); err != nil {
+		log.Errorf("Could not start peer discovery via mDNS: %v", err)
 		return
 	}
 }

shared/p2p/service_norace_test.go

@@ -9,7 +9,7 @@ import (
 func TestLifecycle(t *testing.T) {
 	hook := logTest.NewGlobal()
 
-	s, err := NewServer()
+	s, err := NewServer("")
 	if err != nil {
 		t.Fatalf("Could not start a new server: %v", err)
 	}

shared/p2p/service_test.go

@@ -37,7 +37,7 @@ func init() {
 }
 
 func TestBroadcast(t *testing.T) {
-	s, err := NewServer()
+	s, err := NewServer("")
 	if err != nil {
 		t.Fatalf("Could not start a new server: %v", err)
 	}
@@ -49,7 +49,7 @@ func TestBroadcast(t *testing.T) {
 }
 
 func TestEmitFailsNonProtobuf(t *testing.T) {
-	s, _ := NewServer()
+	s, _ := NewServer("")
 	hook := logTest.NewGlobal()
 	s.emit(Message{}, &event.Feed{}, nil /*msg*/, reflect.TypeOf(""))
 	want := "Received message is not a protobuf message: string"
@@ -59,7 +59,7 @@ func TestEmitFailsNonProtobuf(t *testing.T) {
 }
 
 func TestEmitFailsUnmarshal(t *testing.T) {
-	s, _ := NewServer()
+	s, _ := NewServer("")
 	hook := logTest.NewGlobal()
 	msg := &pubsub.Message{
 		&pubsubPb.Message{
@@ -75,7 +75,7 @@ func TestEmitFailsUnmarshal(t *testing.T) {
 }
 
 func TestEmit(t *testing.T) {
-	s, _ := NewServer()
+	s, _ := NewServer("")
 	p := &testpb.TestMessage{Foo: "bar"}
 	d, err := proto.Marshal(p)
 	if err != nil {
@@ -199,7 +199,7 @@ func testSubscribe(ctx context.Context, t *testing.T, s Server, gsub *pubsub.Pub
 func TestRegisterTopic_WithoutAdapters(t *testing.T) {
 	// TODO(488): Unskip this test
 	t.Skip("Currently failing to simulate incoming p2p messages. See github.com/prysmaticlabs/prysm/issues/488")
-	s, err := NewServer()
+	s, err := NewServer("")
 	if err != nil {
 		t.Fatalf("Failed to create new server: %v", err)
 	}
@@ -240,7 +240,7 @@ func TestRegisterTopic_WithoutAdapters(t *testing.T) {
 func TestRegisterTopic_WithAdapters(t *testing.T) {
 	// TODO(488): Unskip this test
 	t.Skip("Currently failing to simulate incoming p2p messages. See github.com/prysmaticlabs/prysm/issues/488")
-	s, err := NewServer()
+	s, err := NewServer("")
 	if err != nil {
 		t.Fatalf("Failed to create new server: %v", err)
 	}

validator/main.go

@@ -64,6 +64,7 @@ VERSION:
 	app.Flags = []cli.Flag{
 		types.BeaconRPCProviderFlag,
 		types.PubKeyFlag,
+		types.BeaconRPCProviderFlag,
 		cmd.VerbosityFlag,
 		cmd.DataDirFlag,
 		cmd.EnableTracingFlag,
@@ -71,6 +72,7 @@ VERSION:
 		cmd.TraceSampleFractionFlag,
 		cmd.KeystorePasswordFlag,
 		cmd.KeystoreDirectoryFlag,
+		cmd.BootstrapNode,
 		debug.PProfFlag,
 		debug.PProfAddrFlag,
 		debug.PProfPortFlag,

validator/node/p2p_config.go

@@ -16,7 +16,7 @@ var topicMappings = map[pb.Topic]proto.Message{
 }
 
 func configureP2P(ctx *cli.Context) (*p2p.Server, error) {
-	s, err := p2p.NewServer()
+	s, err := p2p.NewServer(ctx.GlobalString(cmd.BootstrapNode.Name))
 	if err != nil {
 		return nil, err
 	}